---Based on this prompt:
"So what happens if two people who have promised their firstborns to separate witches have a child together? Do they both just pop up in the nursery and have a custody battle?"---
*****
The baby is so tiny and odd it barely resembles a proper human being. Yet, as you stand on the other side of the glass case, you can’t help but feel these bursts of pride and joy inside of you.
Your first firstborn.
“Beautiful baby, isn’t it?” comes a voice from behind and you can literally *smell* the smugness in it and that is the exact moment everything goes downhill.
*****
1. Her name is Thelma.
2. Her hair is a wild green mess and her outfit is a staggering combination of incompatible clothing styles.
3. She is one year older which doesn’t make up for the fact that she is an absolutely insufferable stubborn childish little git.
*****
“How wicked”, they say.
“Extraordinary”, they say.
“What were the chances”, they say.
Indeed, you think to yourself. What were the chances of two different witches signing contracts for a firstborn child with two different fools who somehow ended up falling in love with and marrying each other and having that exact child together?
You stare at that unfamiliar face and you can read the same thoughts in those unfamiliar green eyes: ‘How something so simple could get so fucked up?’
*****
“I’ll tell you mine if you tell me yours”.
The clock on the wall of the attorney's waiting room is so loud you would love to throw it out of the window. Each tick is worse than a hammer against your skull. You keep your eyes shut and sigh and allow, “His mom had cancer.”
“He promised you his first child in exchange for his dying mom’s salvation?”, she shifts awkwardly and lets out a what-seems-like an embarrassed chuckle, “Well, mine's just dumb then. The girl wanted a talking dog.”
You actually open your eyes after this one. “She bartered her future child for a *dog*?”
“Priorities”, she drops almost defensively and holds your gaze for a long second before adding, “She did seem hella lonely, though.”
*****
A two-centuries-old creaker keeps mumbling and mumbling and mumbling all this legal nonsense about “unwisely signed contracts” and “the priority rights” and “the inability to reach an agreement” and you are so done with all this bullshit you actually snap at him and promise to curse his dentures and a small eternity later it finally turns out you are now stuck with a joint physical custody.
*****
A week later the door to a now-her room is covered with manually-drawn sigils and runes, her toothbrush is in your bathroom, her ridiculous cauldrons – covered in Doctor Who stickers, for Merlin’s sake! – has taken up all of the space in your small kitchen, those long green strings of her hair can be found absolutely EVERYWHERE, and you are sitting in the middle of your living room – now buried under the piles of her rubbish pens and gaudy notebooks filled with unreadable scribbles of half-finished spells – and you want to scream and scream and screamandscream
*****
8. She keeps her experimental potions in empty plastic water bottles.
9. Her spell books are so chaotic you wouldn’t find required spell in a decade.
10. She messes up your carefully organized herbal storage.
11. She messes up your daily routine.
12. She messes up your sleeping schedule.
13. She messes up your life.
*****
Your cohabitation resembles a battlefield. Each two-steps victory has a one-step throwback.
You make her go do the shopping. She brings back the wrong baby formula, six different brands of ice cream and a frozen pizza.
You ask her to hoover. She tries to enchant the vacuum cleaner. You end up dealing with the devastating outcome.
You set a 11pm curfew. She starts flying off for these ‘little night rides’ and you can’t help but lie for hours, eyes wide open, waiting for the sounds of her return. You pretend that the worry, coiling deep inside, is an irritation.
*****
24. She is surprisingly good with the baby.
“Let me”, she says softly one morning, when Ean – the name was another battle that nearly cost both of you your eyebrows – decides to be particularly difficult, and wails unhappily and won’t allow anything to distract him.
She lifts him and holds him dear and whispers soothing twaddle to him and brushes kisses over his rapidly growing locks and you just sit on the sofa and take in this picture, painted with soft sunlight.
*****
37. She is rubbish at cooking.
But another evening, when Ean is finally fast asleep in his cot, cuddling his favourite stuffed bat, and you are a worn out mess on the sofa, she disappears into the kitchen. There is a gentle clutter of the cookware and the cozy gleam of coals in the fireplace, and you close your eyes and doze off a bit and the next moment there is a *divine* chocolate smell teasing your nostrils, and she’s kneeling beside the sofa with two big mugs in her hands.
You manage to prop yourself up a bit and scoot over and take your cup and thank her. She snuggles up on the opposite side, and you enjoy your drinks – rich tasty flavour with a sprinkle of cinnamon and ginger and some other herbal you can’t quite identify. You let out a content sigh and she flashes a smile at you and you nearly convince yourself that the warmness, spilling in your chest, is from the hot chocolate.
*****
Next evening, though, when she nonchalantly passes you a steaming mug and tucks herself in her corner and starts telling you about her first broom - “I did a 360, dude, I swear; first day in – and I freaking nailed it!” - you can’t be arsed to pretend you haven’t been secretly longing for this moment.
*****
41. She keeps stealing your hoodies.
42. She ruins them with potion stains.
43. And never washes them.
44. You’ve long since stopped complaining about that.
*****
Christmas is a few weeks ahead when you spot some really cute little bottles at the Hobby shop and it’s not as if you’re preparing for some ridiculous gift-exchange but you might as well buy them just in case. You’ve been trying to get rid of those ridiculous plastic bottles of hers for *ages*, anyways.
*****
Christmas day is shite.
You have a quarrel with a customer about the quality of your latest cleaning potion. You lose your wallet despite the fact that it has been specifically enchanted against such cases. You manage to slip and fall on your way to your broom. In addition, it starts snowing heavily so you fly back home being a pathetic miserable freezing downer. Only to find a surprisingly proper-cooked dinner and a small cake with an aggressively red and green frosting on it and a dozen of singing fairies tied to the Christmas tree you have installed together the night before.
“I thought it would be nice to celebrate our first Christmas together”, she says airly, handing Ean over to you, and he babbles enthusiastically at you, undoubtedly telling you all about the amazing things they’ve prepared for this evening. When you look back at her, there is absolutely no way you could be tearing up a bit.
“Merry Christmas”, you say, and she hugs you both and laughs and sets about slicing the cake.
*****
63. Her name is Thelma.
64. She is an insufferable childish little git.
65. She messes up your life.
66. The truth is – you wouldn’t want it any other way.
*****
The end